Electric motors are commonly used in a variety of applications including HVAC systems, washing machines, and dishwashers and typically include a stationary component called a stator and a rotating component called a rotor. The rotor rotates within (or around) the stator when the motor is energized with a driving waveform to rotate a shaft which in turn drives a fan, pump, pulley, or other component.
It is often desirable to know the input power of an electric motor for planning and efficiency purposes. For example, commercial, industrial, or other large-scale operations often simultaneously operate many different electric motors and wish to know the input power of each to determine and allocate system power requirements and/or control the motors for conservation and efficiency purposes.
The input power of an electric motor can be accurately determined with circuitry or other hardware that senses the input current and voltage of the motor. However, such hardware increases the costs and complexity of the motors and is therefore not practical for many low-cost motor applications.
The above section provides background information related to the present invention which is not necessarily prior art.